The present invention exploits principles discovered by the inventors in investigating the gyroscopic response of a femtosecond ring dye laser operating on a rotating platform as shown, for example in FIG. 2. The investigation was carried out at the University of New Mexico Physics and Astronomy Department.
Expected advantages of a mode-locked laser gyro over a conventional CW laser gyro include smaller coupling between the two counterpropagating waves and the absence of mode competition in a homogeneously broadened gain medium. Both features are a result of the fact that the two counterpropagating pulses in a passively mode-locked laser cavity only meet at two points, both outside of the gain medium. However, in a passively mode-locked laser, it is a strong coupling between two counterpropagating waves that establishes the crossing point between the two pulses. It is therefore logical to expect that this same coupling may result in a lock-in of the gyro response. In investigating the dye laser it was demonstrated that, despite this coupling, the femtosecond dye laser has a gyroscopic response without measurable dead band. The present invention builds on this result to provide a solid state gyro with substantially no dead band.